By Bruno Silva, João Paulo Urbano, Gustavo Pinto Pires, Milton dos Santos, Samuell Costa de Souza, and Romario de Carvalho Nunes (Petrobras)
Subsea pipeline integrity management is one of the most demanding challenges in offshore oil and gas. Over the last three years, Petrobras has led a transformative effort to improve ultrasonic thickness measurements (UTM) using Remotely Operated Vehicles (ROVs). The goal: ensure more reliable, accurate, and efficient inspections on critical subsea infrastructure.
Why It Matters
Subsea corrosion can lead to costly failures and unplanned shutdowns. Traditional UTM tools used by ROVs often struggled in severe corrosion scenarios — particularly in internally pitted pipelines. Additionally, outdated hardware, lack of real-time validation, and nonstandard procedures led to inefficiencies and inconsistent data.
What Petrobras Did
Petrobras implemented a series of technical and procedural upgrades, including:
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New ultrasonic modes: Adoption of single-echo and echo-echo techniques in addition to legacy multi-echo mode, greatly improving performance in corroded regions.
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A-scan integration: Visual waveform feedback (A-scan) allows real-time verification of signal quality, helping operators reject false readings.
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Hardware upgrades: New ROV-compatible transducers were developed with better pressure resistance, sealing, and durability (acrylic protection replaced silicone).
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Custom handling tool (handle): Redesigned adapter allowed the tool to align properly with curved surfaces, expanding access to difficult-to-reach areas.
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Certified professionals onboard: Petrobras mandated ABENDI-certified inspectors specialized in ROV-based UTM to ensure procedural quality.
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Underwater calibration: UTM tools are now calibrated at inspection depth, addressing the effects of hydrostatic pressure.
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Standardization: A Petrobras-specific UTM guideline was created to unify procedures, reporting templates, and A-scan analysis.
The Results
After over 100 services executed using the new approach, Petrobras reported:
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+23% increase in inspection coverage
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>99.9% valid readings in accessible zones
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–95% reduction in downtime from UTM failures
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–50% faster average service time
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Millions in savings from reduced vessel hours and rework
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50% of current readings would not be possible without the added ultrasonic modes
What’s Next
A new ROV handle design — currently under patent — is being developed with impact-absorbing features, 360° flexibility, and remote imaging. This will enable reliable readings in even more geometrically complex or sensitive areas.
Final Thoughts
This initiative is a clear case of field-driven innovation. By combining ultrasonic technique upgrades, ROV tool redesign, and procedural rigor, Petrobras has significantly improved the quality and efficiency of subsea inspections — setting a benchmark for the offshore sector.
Want to learn more or connect about ultrasonic innovations offshore?
Reach out to Bruno Silva or João Paulo Urbano via [LinkedIn] or SPE Connect.